I don't know if the op is still following this thread or not, but I think a 150 or maybe even a hot 125 might work. I basing this somewhat on the fact that I grew up in Clarksville TN. It's changed a lot since i lived there, and I'm not sure which way the op goes to get on base, but one of the major roads leading to base is a lot of stop and go, 45ish mph traffic, esp. during rush hour. Then when your on base, it's a lot (unless it's changed) of 25 and 35 and those speeds are strictly enforced. i could imagine a scooter being kinda perfect for clarksville/fT campbell.

I first took to the road - powered that is, by a motor rather than pedals - in 1967, aboard a Honda C65 Supercub which had a top-end of 45mph. For the next 24 months (or so) that was my own limit speed-wise.